Answer:
Step-by-step explanation:
total height, H = 113 inches
height of each stair case, h = 7.25 inches
Number of stair case, n = total height / height of each stair case
n = 113 / 7.25 = 15.6
Answer:
d
Step-by-step explanation:
Using the Cosine rule to find ∠ A
cosA = 
= 
= 
=
, then
∠ A =
(
) ≈ 84.9° ( to 1 dec. place )
Answer:
The percentage is 
Step-by-step explanation:
From the question we are told that
The population mean is 
The standard deviation is 
The percent of people who write this exam obtain scores between 350 and 650

Generally




From the z-table 
and 
=> 
=> 
Therefore the percentage is 
X, y - the numbers
The sum of the two numbers is 9.

If one number is subtracted from the other, the result is 3.

Solve the system of equations:

The numbers are 6 and 3.
12in=1ft
39/12=3.25ft
1m=3.25ft
times 4 both sides
4m=13ft
12ft
C